In the course of a long compositional career, the defining feature of the music of the Finnish composer Einojuhani Rautavaara, who has died at the age of 87, was its stylistic adaptability. The distinctive Rautavaara soundworld familiar from his later, internationally successful works evolved only gradually, achieving its fully recognisable form in the 1980s.

A prolific composer, he wrote eight symphonies, nine operas, 12 instrumental (and one choral) concertos, plus a wide variety of orchestral, chamber, instrumental, choral and vocal works. He was also a highly perceptive writer on music and a teacher: many Finnish composers who have enjoyed international success were his pupils, including Paavo Heininen and Kalevi Aho.

His output embraced a wide range of styles: Russophile and neoclassical in the 1950s (his first two symphonies), serialinthe mid-60s (the Third and Fourth Symphonies), and neo-romantic in the 70s, with transitional stages in between. Finally, in the 80s, he synthesised a truly personal, immediately recognisable idiom from elements of the compositional manners he had passed through. In 1991 Rautavaara wrote of his “need for ... and belief in” such synthesis: “Naturally, the linking together of various (and to some people contradictory) systems must of necessity come to break the taboos of each system. But then I also believe that all artistic taboos are evidence of shortsightedness (in time and space) and often of racism.”

The extraordinary success his music enjoyed from the mid-1980s onwards, for example with his Seventh Symphony, Angel of Light (1994), was in part prepared for him by the runaway successes enjoyed by two of his contemporaries: the Estonian Arvo Pärt and the Polish composer Henryk Górecki. Rautavaara’s symphony sounded like neither of these, however, lacking (intentionally) the former’s “holy minimalism” and not marking a departure from his normal path, as the latter’s popular Symphony of Sorrowful Songs did.

Rautavaara’s father, Eino, was an opera singer and cantor, and his mother, Elsa, a doctor, who encouraged the boy to learn the piano; both parents died before his 16th birthday. He went to live with his maternal aunt, Hilja Teräskeli, and stayed in Helsinki, where he was born, or in its suburbs for the rest of his life, eventually in the house once owned by the great choral conductor Heikki Klemetti. He studied composition at the Sibelius Academy, principally under Aarre Merikanto, receiving his diploma in 1957 from the University of Helsinki.

His early brass and percussion suite A Requiem for Our Time (1953) won the international Thor Johnson brass competition, establishing him as a composer while still a student. The work so impressed the octogenarian Sibelius that in 1955 he recommended Rautavaara for a scholarship to the US. There the young composer received tuition from Aaron Copland, Vincent Persichetti and the serialist Roger Sessions at the Juilliard and Tanglewood schools.

On his return to Finland, Rautavaara spent time ferrying dignitaries back and forth to visit Sibelius at his home in Hämeenlinna. In 1957 Rautavaara travelled to Switzerland to be a pupil of Wladimir Vogel and the next year went to Cologne to attend Rudolf Petzold’s classes at the Musikhochschule.

His adoption of the 12-note and serial methodologies prevalent in central European composition was highly radical for Finland at the time, but in the early 1960s Rautavaara courted celebrity and controversy in equal measure with a series of advanced scores that put him at the forefront of Finnish composition, alongside Joonas Kokkonen and Erkki Salmenhaara.

Rautavaara’s Third Symphony (1961) created a stir with its elegant and atmospheric blending of serial processes within a Brucknerian soundworld, and recordings in recent years have elevated it to the status of a minor modern classic. Symphony No 4 (1964), by contrast, failed in attempting a more advanced track and, after an equally unsuccessful rewrite in 1969, was withdrawn. It was replaced in his symphonic canon by the totally serial (and non-symphonic) suite Arabescata (1964), one movement of which used graphic rather than conventional notation, and which caused a public disagreement with the celebrated conductor Paavo Berglund.

His first opera, The Mine (1957-58), received its premiere in a much debated and criticised premiere on Finnish television, and only in recent years has it been rehabilitated (and recorded), in its twice-revised final version.

Rautavaara’s problems with his Fourth Symphony coincided with a general disenchantment with serialism and a marital crisis (resulting eventually in divorce). In his music from the late 1960s onwards, such as the Cello Concerto No 1 (1968) and First Piano Concerto (1969), he began to forge a more intuitive style as a composer, a process that reached fruition nearly two decades later with his opera Thomas (1982-85) and the glorious single-movement Fifth Symphony (1985).

Along the way, he had produced his first really widespread popular success, the “concerto for birds and orchestra” Cantus Arcticus (1972), in which he replaced the conventional instrumental soloist with taped birdsong from Arctic Finland. At the same time, he produced perhaps his deepest choral masterpiece, Vigilia, a large-scale unaccompanied setting of the Orthodox all-night vigil of St John the Baptist in which the composer recalled a “vision-inducing childhood visit to the island monastery of Valamo in the middle of Lake Ladoga just before the winter war in 1939”.

Although it bears no other title, the Fifth Symphony belongs to a stream of works central to which is the image of the angel. The series began with Angels and Visitations in 1978 (though the organ concerto Annunciations from a year earlier is clearly related) and the double-bass concerto Angel of Dusk in 1980, and continued into the 1990s with the Seventh Symphony, Angel of Light.

That work’s symphonic predecessor, the Sixth, Vincentiana (1992), was constructed from orchestral material taken from his opera Vincent (1989), based on the life of Van Gogh. For his eighth opera, Aleksis Kivi (1997), Rautavaara turned to another tortured creative artist, the Finnish author of The Isle of Bliss, itself the subject of a fine orchestral tone poem in 1995. His final opera was Rasputin, composed in 2001-03 specifically for the Finnish bass Matti Salminen, who took the title role for Finnish National Opera. Its reception was mixed, its theatrical craft being admired while the musical language was described as – ironically – “old-fashioned”.

Despite severe health problems following a ruptured aorta in the early 2000s, Rautavaara continued to compose, his final works including a pair of concertos for percussion, Incantations (2008) and the Cello Concerto No 2 (2009), the fifth Canto for string orchestra (2011), smatterings of chamber, choral and vocal works (including a Missa a Cappella in 2010-11, a setting of verses from the Rubaiyat and Homage to an Old Composer), Mirroring for piano (2014) and a Fantasia for violin and orchestra for Anne Akiko Meyers, completed last year.His Christmas Carol was commissioned by King’s College, Cambridge, and sung at the Festival of Nine Lessons and Carols broadcast in 2010.

Rautavaara married Mariaheidi (originally Heidi Maria) Suovanen, an actor, in 1959. The marriage was dissolved in 1984. In that year he married Sinikka Koivisto, who survives him, as do two sons, Markojuhani and Olof, and a daughter, Yrja.

• Einojuhani Rautavaara, composer, born 9 October 1928; died 27 July 2016

• This article was amended on 29 July 2016, correcting the name of the violinist Anne Akiko Meyers.